how to prevent a connected charger from draining battery when not charging?

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • flat-earther
    Senior Member
    • Dec 2022
    • 111
    • palestine
    #1

    how to prevent a connected charger from draining battery when not charging?

    I have an RC radio handset(Taranis QX7) which doesn't have internal battery charger which means I had to remove the battery every time I needed to charge it.
    So to improve it, I added a 15W USB-C charger board(link) inside and soldered it to the same connector on the PCB where the battery plugs into, great, now I can simply charge it with a USB-C cable.

    but the problem I found is that after the radio sat for two weeks without being used the 2S 18650 battery that I'm using was at 4.2V!
    So the battery is backfeeding the charger and being drained.

    How can I prevent the battery from being drained?
    Maybe some kind of diode between the charger and PCB?
    If not then is it possible to add a mosfet between the charger and the PCB, and somehow make the mosfet turn on while charging but then turn off otherwise so no current can flow from the battery to charger?
    I don't know if those ideas are possible because I'm not knowledgeable enough about electronics, what do you guys suggest?
    Attached Files
    Tags: None
    Previous template Next

    Related Topics

    Collapse
    • Bowline
      Dell E6400 PT434 type Battery Charging Stuck at 1%. Battery Pinouts?
      by Bowline
      My question pertains to understanding the control circuity inside a Dell PT434 type battery used in Dell E6400, E6410 and other Dell notebooks?

      Does anyone have a circuit diagram for the inside of a Dell PT434 battery and/or a description of how the control lines work to control this battery?

      My reason for asking is I have a battery which I cannot get to charge beyond 1% in a Dell E6410 or E6400.
      The LED bar graph charge indicator on the battery shows one LED lighted when the info button is pressed.
      I have tried multiple different Dell power adapters. My Dell...
      06-11-2025, 10:13 AM
    • sam_sam_sam
      Bauer tool battery pack charging with a HERCULES charger modification
      by sam_sam_sam
      The Bauer power tool battery charger just has to many issues with the charger over heating because I several HERCULES Hercules battery chargers that are 3 amp charge and because they have gone on quite a few times over the years before they came out with the fan cooling battery charger I going to modify one so I can charge Bauer battery packs faster than the crape battery charger that they have

      Here is how this modification is going to be done I taking a 1.5 amp hour battery enclosure and gutting it removing the battery cells and replacing some Ryobi 1.5 amp hour battery pack that...
      05-06-2023, 12:17 PM
    • sam_sam_sam
      Milwaukee M18 HD12.0 (12 amp hour battery pack) unbalanced failure charger refusing
      by sam_sam_sam
      I have two Milwaukee 12 amp hours battery packs that have an issue with battery cells very unbalanced these are probably over 4 years old and been heavily used in the past but now get occasionally used heavily and when I went to use the grinder tool the battery lost battery battery power very quickly so I decided to open it up and found some battery cells voltage from 3.6 to 4.1 no wonder the battery charger was not fully charging them 3 out of 4 LEDs were on meaning that it was only 75% charged

      So I have put them on the battery testing machine to drain each battery cell down to...
      09-04-2022, 04:45 PM
    • code share
      Lenovo P43s won't boot with internal battery connected – looking for help diagnosing battery issue
      by code share
      Hi everyone,

      I'm having an issue with my Lenovo ThinkPad P43s. The laptop does not power on when the internal battery is connected, but it works fine on AC power alone (battery disconnected). Once the battery is reconnected, the system becomes completely unresponsive — no lights, no fan spin, nothing.

      Here's what I've tried so far:
      • Power/EC reset (held power button for 60 seconds with battery and AC disconnected)
      • Booted successfully on AC power only with the battery disconnected
      • Visual inspection of the battery — no swelling, burn marks, or connector damage
      • Battery
      ...
      04-21-2025, 12:50 PM
    • Thomasraud
      Dell Vostro 3550 (v A01 with BQ24707) Plugged in, Not Charging
      by Thomasraud
      Hello,


      i have similar problem as https://www.badcaps.net/forum/showthread.php?t=37828
      QUOTED
      -It works on charger (without battery connected-only charger)
      -It works on battery (without charger connected-only battery)
      -& it also works when plugged in battery & charger, but it's not charging the battery
      //Confirming, i have same issue, but problem started from charger, centre PIN is outputing 10V+ and jumping randomly 19V


      and..


      QUOTE
      The IC cannot maintain the input current level      ...
      06-28-2022, 06:47 PM
    • Loading...
    • No more items.
    Working...